I had the same problem three times already on my Caminos. If you can't put your backpack in the drier, than it's better to stop for a day, buy a spray that contains permethrin (usually you can get some in ferreterias) and a big black (!!!) plastic trash bag, spray the backpack and other stuff you don't want to machine wash (boots etc), put everything in the bag and leave it on the sun. Wash and dry (you may repeat drying process) clothes and sit back with a cold beer in your hand.
I'm trying to be rational. No signs of an infestation now or before on the beds, no signs of any of the live little buggers in my stuff, which has all been washed and dried - egg situation is concern. I'll hit Logroño tomorrow and do the whole thing again.
I can bend my aarn pack into the dryer but that doesn't seem like the best idea.
I ended up with a somewhat deformed Osprey pack from several times tumbling in a dryer. The plastic insert in the back became curved like a sway back. See if you can remove anything like that. Otherwise, I agree with the permethrin spray, with or without the sun treatment.
To kill bedbugs, the dryer alone (with dry clothes from the start) will be faster and more effective than putting wet clothes in.
I jammed it in the dryer and it seems to have survived. Came out piping hot.
Feel better about that than permethrin, which hasn't really shown to be effective in research tests (sorry for bluntness there - it's been a long day and I haven't slept since going eyeball to eyeball with Chinchin at 2 this morning).
I'm not that psyched about the way everything else got dried, but we were pushing through a ton of stuff through a home washing machine at the albergue.
Logroño for the commercial re-do. I've got a bunch of stuff that simply can't be dried, too (principally my CPAP, which is like Netflix for a CO2 loving bed bug), and I had the USB slot open for nesting (it's got a handy phone charging capability). I'm banking on the odds that if a set of eggs was laid, I dryered the spot it was laid. And that it really is not yet an infestation (and that eggs were laid everywhere).
I'm back to best practices tonight - in the same albergue. Banking that the lack of external evidence of infestation means they were rogue operators in another room.